LG2A

Laboratoire de Glycochimie, des Antimicrobiens
et des Agroressources UMR 7378 CNRS

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Actualités et Publications

Secondary Metabolites from Gorgonian Corals of the Genus Eunicella: Structural Characterizations, Biological Activities, and Synthetic Approaches,

Matulja, D.; Kolympadi Markovic, M.; Ambrožić, G.; Laclef, S.; Pavelić, S. K.; Marković, D.

Molecules 2019, 25, 129.

Gorgonian corals, which belong to the genus Eunicella, are known as natural sources of diverse compounds with unique structural characteristics and interesting bioactivities both in vitro and in vivo. This review is focused primarily on the secondary metabolites isolated from various Eunicella species. The chemical structures of 64 compounds were divided into three main groups and comprehensively presented: a) terpenoids, b) sterols, and c) alkaloids and nucleosides. The observed biological activities of depicted metabolites with an impact on cytotoxic, anti-inflammatory, and antimicrobial activities were reviewed. The most promising biological activities of certain metabolites point to potential candidates for further development in pharmaceutical, cosmetic, and other industries, and are highlighted. Total synthesis or the synthetic approaches towards the desired skeletons or natural products are also summarized.

Rhodium-Catalyzed Aqueous Biphasic Olefin Hydroformylation Promoted by Amphiphilic Cyclodextrins,

Cocq, A.; Bricout, H.; Djedaïni-Pilard, F.; Tilloy, S.; Monflier, E.

Catalysts 2020, 10, 56.

Hydroformylation is an industrial process that allows for the production of aldehydes from alkenes using transition metals. The reaction can be carried out in water, and the catalyst may be recycled at the end of the reaction. The industrial application of rhodium-catalyzed aqueous hydroformylation has been demonstrated for smaller olefins (propene and butene). Unfortunately, larger olefins are weakly soluble in water, which results in very low catalytic activity. In an attempt to counteract this, we investigated the use of amphiphilic oleic succinyl-cyclodextrins (OS-CDs) synthesized from oleic acid derivatives and maleic anhydride. OS-CDs were found to increase the catalytic activity of rhodium during the hydroformylation of water-insoluble olefins, such as 1-decene and 1-hexadecene, by promoting mass transfer. Recyclability of the catalytic system was also evaluated in the presence of these cyclodextrins.

Comparative binding and uptake of liposomes decorated with mannose oligosaccharides by cells expressing the mannose receptor or DC-SIGN,

Gao, H.; Gonçalves, C.; Gallego, T.; François-Heude, M.; Malard, V.; Mateo, V.; Lemoine, F.; Cendret, V.; Djedaini-Pilard, F.; Moreau, V.; Pichon, C.; Midoux, P.

Carbohydr. Res. 2020, 487, 107877.

Mannose Receptor (MR) and DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) are two mannose-specific targets for antigens carried by liposomes but DC-SIGN is more specific of DCs. Here, DC targeting is addressed by using DPPC/DOPE liposomes decorated with a series of diether lipids with a polar head of either a mannose (Man), tri-antenna of α-d-mannopyranoside (Tri-Man), [Manα1-3(Manα1-6)Man] (Man-tri), pseudo-Man4 (PMan4) or pseudo-Man5 (PMan5). Liposomes decorated with Man-Tri show the highest binding and internalization in cells expressing DC-SIGN and in human monocytes-derived DCs. Conversely, cells expressing MR bind and take up Tri-Man liposomes 3-fold higher than Man-tri liposomes. Comparatively, liposomes decorated with PMan4 and PMan5 do not show any advantages. Overall, the results indicate that liposomes decorated with Man-tri residues are more selective toward DCs than those with Tri-Man thanks to better recognition by DC-SIGN.

Curvature as a Collective Coordinate in Enhanced Sampling Membrane Simulations,

Bouvier, B.

J. Chem. Theory Comput. 2019.

The plasticity of membranes plays an important functional role in cells, cell components, and micelles, where bending, budding, and remodeling implement numerous recognition and communication processes. Comparatively, molecular simulation methods to induce, control, and quantitatively characterize such deformations remain scarce. This work defines a novel collective coordinate associated with membrane bending, which strives to combine realism (by preserving the notion of local atomic curvatures) and low computational cost (allowing its evaluation at every time step of a molecular dynamics simulation). Enhanced sampling simulations along this conformational coordinate provide convenient access to the underlying bending free energy landscape. To showcase its potential, the method is applied to three state-of-the-art problems: the determination of the bending free energy landscape of a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) bilayer, the formation of a POPE liposome, and the study of the influence of the Pseudomonas quinolone signal on the budding of Gram-negative bacterial outer membranes.

Conversion of Chitin in Ionic Liquids,

Hadad, C.; Husson, E.; Van Nhien, A. N.

Encyclopedia of Ionic Liquids 2019, 1-6.

Present in the exoskeleton of arthropods or in the cell walls of fungi, chitin belongs to the most abundant polysaccharides after cellulose and is composed of linear chains of β-(1 → 4)- N-acetyl-D-glucosamine. There are three types of chitins (α-, β-, γ-chitin) with different crystallographic structures. Among them, α-chitin, the most prominent form, is arranged in an antiparallel fashion and is found in both crustacean and insects’ sources [ 21]. Despite its excellent biodegradability, biocompatibility, antimicrobial activity, nontoxicity, low immunogenicity, and good mechanical properties, chitin remains underutilized. This limitation in terms of application is mainly due to: (i) the low extraction efficiency, (ii) the extraction costs excessively high and not environmentally friendly, and (iii) the lack of solubility of this hydrophobic biopolymer. To overcome this weak solubility, pretreatments (chemical, mechanical, enzymatic, …) are interesting alternatives by...

6th EPNOE International Polysaccharide Conference

José KOVENSKY, Véronique BONNET, Albert NGUYEN VAN NHIEN, Mariam NDOUR, Gaël HUET, Maria Emilia CANO

Aveiro PORTUGAL 21st– 25th October 2019

Le laboratoire LG2A a récemment participé à la 6ème Conférence Internationale sur les Polysaccharides, à Aveiro (Portugal) du 21 au 25 octobre. EPNOE a pour objectif de réunir des chercheurs du monde universitaire et du secteur industriel travaillant sur des thèmes de R & D liés aux polysaccharides ou intéressés par ce sujet, de diffuser les résultats et de promouvoir une plateforme de mise en réseau permettant des interactions étroites entre le monde universitaire et l'industrie.




Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources
UMR 7378 CNRS
10 rue Baudelocque
80039 Amiens Cedex
tel/fax : 33 (0)3 22 82 75 60
N° SIRET : 19801344300017